External eye diseases such as blepharoconjunctivitis, meibomian gland dysfunction, and chalazia are common causes of chronic ocular disease and irritation. In recent years it has become apparent that abnormalities in meibomian gland lipids may play a significant role in the pathophysiology of such ocular problems. The ultimate objective of this study is to determine the role of meibomian gland lipids in such external eye diseases. We plan to develop and utilize ultramicro techniques such as glass capillary gas chromatography and multiple ion monitoring in mass spectrometry with a data system in the analysis of the very small samples (approximately 50 to approximately 300 micron.) of lipids obtainable from the meibomian glands of patients with such eye diseases. We will first examine meibomian gland lipids from "normals" and then compare these findings with those from patients with various external eye diseases. At the present time very little information is available concerning the role of meibomian gland lipids in ocular disease since the small amount of material available for study has not been sufficient to utilize standard lipid chemistry techniques. With the development of microtechniques as will be utilized in the present proposal, such studies are feasible as indicated by our preliminary work. In addition to disease states mentioned above, meibomian gland lipids are involved in tear film dynamics and contact lens wear problems, and these will be the subject of future investigations.